@article{ordersize,
title={Indexing and Querying XML Data for Regular Path Expressions},
author={Quanzhong Li and Bongki Moon},
year={2001}
}

@article{dewey,
title={Storing and Querying Ordered XML Using a Relational Database System},
author={Igor Tatarinov and Stratis D. Viglas and Kevin Beyer and Jayavel Shanmugasundaram and Eugene Shekita and  Chun Zhang},
year={2002}
}